Syz reports the following WARNING:
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: CPU: 3 PID: 5384 at net/mac80211/main.c:287
ieee80211_link_info_change_notify+0x1c2/0x230
Modules linked in:
RIP: 0010:ieee80211_link_info_change_notify+0x1c2/0x230
Call Trace:
<TASK>
ieee80211_set_mcast_rate+0x3e/0x50
nl80211_set_mcast_rate+0x316/0x650
genl_family_rcv_msg_doit+0x20b/0x300
genl_rcv_msg+0x39f/0x6a0
netlink_rcv_skb+0x13b/0x3b0
genl_rcv+0x24/0x40
netlink_unicast+0x4a2/0x740
netlink_sendmsg+0x83e/0xce0
sock_sendmsg+0xc5/0x100
____sys_sendmsg+0x583/0x690
___sys_sendmsg+0xe8/0x160
__sys_sendmsg+0xbf/0x160
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
The execution process is as follows:
Thread A:
ieee80211_open()
ieee80211_do_open()
drv_add_interface() //set IEEE80211_SDATA_IN_DRIVER flag
...
rtnl_newlink
do_setlink
dev_change_flags
...
__dev_close_many
ieee80211_stop()
ieee80211_do_stop()
drv_remove_interface() //clear flag
...
nl80211_set_mcast_rate()
ieee80211_set_mcast_rate()
ieee80211_link_info_change_notify()
check_sdata_in_driver() //WARNING because flag is cleared
When the wlan device stops, the IEEE80211_SDATA_IN_ DRIVER flag is cleared.
And then after the set mcast rate command is executed, WARNING is generated
because the flag bit has been already cleared.
Fixes: 591e73ee3f73 ("wifi: mac80211: properly skip link info driver update")
Reported-by: syzbot+bce2ca140cc00578ed07@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
---
v2: modify commit info
---
net/mac80211/main.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 24315d7b3126..f79e2343dddd 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -285,6 +285,9 @@ void ieee80211_link_info_change_notify(struct ieee80211_sub_if_data *sdata,
if (!changed || sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
return;
+ if (!ieee80211_sdata_running(sdata))
+ return;
+
if (!check_sdata_in_driver(sdata))
return;
--
2.34.1
